1. Field of the Invention
The present invention relates generally to the interconnection of electronic elements to electronic motherboard assemblies. More particularly, the present invention involves electrically connecting electronic elements, such as integrated circuits and chips, to a silicon motherboard by laser induced metallization.
2. Description of Related Art
An extremely important aspect of any complex electronic assembly is the interconnection of the electronic elements with the motherboard. Previous interconnections between integrated circuits in such hybrid assemblies have been accomplished using wire bonding or tab bonding. Both of these techniques are bulky and introduce wire inductances. These inductances preclude distortion-free operation of the assembly at high frequencies. Accordingly, there presently is a need to provide improved interconnections between electronic elements and their motherboard.
Laser induced metallization has been used to deposit metal layers onto complex circuit boards U.S. Pat. Nos. 4,340,617 and 4,359,485 disclose exemplary processes in which an organometallic layer is exposed to laser radiation to provide selective conversion of the layer into metal. These laser writing processes--also known as laser pantography--have been in use since the early l980's. An exemplary laser pantography system is discussed in the article by McWilliams et al., entitled "Wafer-Scale Laser Pantography: Fabrication of n-Metal-Oxide-Semiconductor Transistors and Small-Scale Integrated Circuits by Direct-Write Laser-Induced Pyrolitic Reactions," (Appl. Phys. Lett. 43 (10), Nov. 15, 1983). The contents of these patents and articles are hereby incorporated by reference.
The above-mentioned laser pantography techniques have been used to convert metallo-organic coatings into metal layers on planar surfaces. However, the use of such laser induced conversion techniques has not been extended to writing on non-planar surfaces.